The Robotic Manipulation
Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.
The Cruciferous Vegetable Amplification
Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.
The Zazzy Substitution
The guys are concerned as Sheldon searches for an alternative to human companionship.
The Hot Troll Deviation
An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.
The Desperation Emanation
Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.
The Irish Pub Formulation
Leonard keeps an affair a secret from Sheldon, Howard and Raj.
The Apology Insufficiency
Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.
The 21-Second Excitation
While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.
The Boyfriend Complexity
Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a telescope.
The Alien Parasite Hypothesis
Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who would be the better superhero.
The Justice League Recombination
The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as the Justice League.
The Bus Pants Utilization
Leonard's idea for a smartphone app derails his friendship with Sheldon.
The Love Car Displacement
Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.
The Thespian Catalyst
Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasies about a friend's girlfriend.
The Benefactor Factor
A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of science.
The Cohabitation Formulation
As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his relationship with Raj's sister.
The Toast Derivation
Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard is the center of the group.
The Prestidigitation Approximation
Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it impossible to continue being friends with Penny.
The Zarnecki Incursion
The guys go all out to help Sheldon find the person responsible for hacking his online gaming account, while the girls' hatred for Priya increases.
The Herb Garden Germination
Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes his relationship with Bernadette to even higher level.
The Agreement Dissection
When Priya finds a loophole in the roommate agreement to throw Sheldon out for the night, Penny, Amy and Bernadette take him to a nightclub.
The Wildebeest Implementation
Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and his girlfriend.
The Engagement Reaction
When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the hospital.
The Roommate Transmogrification
When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny does something she's regrets.